Which statement correctly compares wet and dry spent fuel storage?

Which statement correctly compares wet and dry spent fuel storage?

• A. Wet storage uses water cooling while dry storage uses active, pumped cooling.
• B. Wet storage is designed for long-term modular storage.
• C. Dry storage requires shielding during transport; wet storage does not.
• D. Wet storage uses water cooling and shielding; dry storage uses passive cooling in modular casks.

Answer: (D)

The idea being tested is how cooling and shielding differ between wet and dry spent-fuel storage. In wet storage, spent fuel sits in a water-filled pool where the water acts as both coolant and radiation shield. The heat from the fuel is carried away by actively circulating water, and the water also reduces radiation exposure. In contrast, dry storage uses passive cooling in sealed modular casks; the fuel is kept in a robust steel/concrete container that provides shielding, and heat is dissipated without active pumping, simply through natural convection and conduction to the surroundings. This approach is intended for long-term storage (and can be used for transport as well, with the appropriate certified cask). The other statements don’t fit because: wet storage relies on active cooling and water shielding, not just passive water; wet storage is not designed for long-term modular storage in the way dry storage is; and shielding is needed during transport for both methods, with dry storage using the cask’s shielding rather than water.

The idea being tested is how cooling and shielding differ between wet and dry spent-fuel storage. In wet storage, spent fuel sits in a water-filled pool where the water acts as both coolant and radiation shield. The heat from the fuel is carried away by actively circulating water, and the water also reduces radiation exposure. In contrast, dry storage uses passive cooling in sealed modular casks; the fuel is kept in a robust steel/concrete container that provides shielding, and heat is dissipated without active pumping, simply through natural convection and conduction to the surroundings. This approach is intended for long-term storage (and can be used for transport as well, with the appropriate certified cask).

The other statements don’t fit because: wet storage relies on active cooling and water shielding, not just passive water; wet storage is not designed for long-term modular storage in the way dry storage is; and shielding is needed during transport for both methods, with dry storage using the cask’s shielding rather than water.